/**
 * The driver program for the 4bit virtual machine.
 * Commandline options:
 *   -d specifies debug mode, which will print the state of the machine at each
 *   executiion step
 *   [filename] filepath of the the prog to run
 *
 * @author mbk
 * @version 1
 */
public class VMDriver {

    /**
    * main driver program for the VM.
    * @param args The commandline arguments
    */
    public static void main(String[] args) {

        String usageString = "usage: java VMDriver <program> [-d]";

        try {
            if (args.length != 1 && args.length != 2) {
                System.err.println(usageString);
                return;
            }

            VM vm = new VM(args[0]);

            if (args.length == 2 && args[1].equals("-d")) {
                vm.debugModeOn();
            }

            while (vm.isRunning()) {
                vm.step();
            }
        } catch (Exception e) {
            System.err.println(e);
        }
    }
}